1. Field of Technology
The present invention relates to a heat recovery steam generator, particularly to a combined cycle power generation facility.
2. Background of Art
The combined cycle power generation facility uses both a gas turbine and steam turbine to generate electric power. In the gas turbine, a compressor compresses intake air to produce compressed air, a combustor burns fuels with the compressed air to produce combustion gas and a turbine is driven by the combustion gas, whereby electric power is generated. A heat recovery steam generator generates high-temperature and high-pressure steam by using exhaust gas (exhaust heat) exhausted from the gas turbine, and a steam turbine is driven by said generated steam.
when the intake air is taken into the gas turbine, a filter provided with the gas turbine removes dust and dirt contained in atmosphere. However, the dust and dirt which cannot be removed by the filter come inside and stick onto the compressor vane. This will gradually reduce efficiency of the compressor and efficiency of electric power generation, and require frequent washing operation. Methods have been proposed in the prior art to determine the time of performing the washing operation. In one of such methods, for example, the corrected compressor efficiency is computed by subtracting the influence of the inlet air temperature of the compressor and inlet guide vane angle by correction. Then comparison is made between the corrected compressor efficiency and the initial value of the compressor efficiency subsequent to previous washing operation, whereby timing for washing operation is determined (e.g. Patent Document 1).
[Patent Document 1] Japanese Application Patent Laid-Open Publication No. Hei 08-296453